概率论与数理统计
mean
Object mean({int dim = -1})
求均值
test
import 'package:flutter_matrix/matrix_type.dart';
main() {
var mt = Matrix.fromList([
[1, 2, 3, 4],
[double.infinity, 2, 2, 3],
[0, 4, 6, -2]
]);
print(mt.mean(dim: 0));
print(mt.mean(dim: 1));
print(mt.mean(dim: 2));
}
output
[2.5, Infinity, 2.0]
[Infinity, 2.0, 2.75, 1.25]
Infinity
median
Object median({int dim = -1})
求中位数
test
import 'package:flutter_matrix/matrix_type.dart';
main() {
var mt = Matrix.fromList([
[1, 2, 3, 4, 6, 7, 10],
[double.infinity, 2, 2, 3, 4, 7, -65],
[0, 4, 6, -2, 1, -2, -2]
]);
print(mt.median(dim: 0));
print(mt.median(dim: 1));
print(mt.median(dim: 2));
}
output
[4.0, 3.0, 0.0]
[1.0, 2.0, 3.0, 3.0, 4.0, 7.0, -2.0]
3.0
mode
Object mode({int dim = -1})
求众数
test
import 'package:flutter_matrix/matrix_type.dart';
main() {
var mt = Matrix.fromList([
[1, 2, 3, 4, 6, 7, 10],
[double.infinity, 2, 2, 3, 4, 7, -65],
[0, 4, 6, -2, 1, -2, -2],
[double.infinity, 2, 2, 3, 4, 7, -65],
]);
print(mt.mode(dim: 0));
print(mt.mode(dim: 1));
print(mt.mode(dim: 2));
}
output
[1.0, 2.0, -2.0, 2.0]
[Infinity, 2.0, 2.0, 3.0, 4.0, 7.0, -65.0]
2.0
shuffle
void shuffle({int? seed, int dim = -1})
随机打乱，seed是随时数种子
test
import 'package:flutter_matrix/matrix_type.dart';
main() {
data_format = "%2.2f";
Matrix.linspace(start: 0, end: 1, row: 5, column: 10)..visible();
var m12 = Matrix.linspace(start: 0, end: 1, row: 5, column: 10);
var m13 = Matrix.linspace(start: 0, end: 1, row: 5, column: 10);
var m14 = Matrix.linspace(start: 0, end: 1, row: 5, column: 10);
m12..shuffle(dim: 0)..visible();
m13..shuffle(dim: 1)..visible();
m14..shuffle(dim: 10)..visible();
}
output
[
[ 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18]
[ 0.20 0.22 0.24 0.27 0.29 0.31 0.33 0.35 0.37 0.39]
[ 0.41 0.43 0.45 0.47 0.49 0.51 0.53 0.55 0.57 0.59]
[ 0.61 0.63 0.65 0.67 0.69 0.71 0.73 0.76 0.78 0.80]
[ 0.82 0.84 0.86 0.88 0.90 0.92 0.94 0.96 0.98 1.00]
]
[
[ 0.06 0.18 0.14 0.16 0.02 0.12 0.08 0.04 0.10 0.00]
[ 0.29 0.20 0.39 0.31 0.22 0.35 0.37 0.27 0.24 0.33]
[ 0.41 0.47 0.57 0.49 0.51 0.55 0.43 0.45 0.59 0.53]
[ 0.67 0.73 0.63 0.71 0.61 0.65 0.76 0.80 0.69 0.78]
[ 1.00 0.94 0.98 0.92 0.96 0.88 0.90 0.86 0.84 0.82]
]
[
[ 0.20 0.84 0.04 0.27 0.29 0.92 0.53 0.35 0.98 0.80]
[ 0.82 0.22 0.24 0.06 0.90 0.51 0.94 0.96 0.16 0.18]
[ 0.41 0.02 0.86 0.88 0.49 0.31 0.12 0.76 0.57 0.39]
[ 0.00 0.63 0.45 0.67 0.08 0.10 0.73 0.14 0.78 1.00]
[ 0.61 0.43 0.65 0.47 0.69 0.71 0.33 0.55 0.37 0.59]
]
[
[ 0.55 0.41 0.96 0.27 0.92 0.82 0.57 0.39 0.73 0.63]
[ 0.88 0.29 0.43 0.98 0.22 0.78 0.94 0.45 0.76 0.37]
[ 0.69 0.16 0.84 1.00 0.90 0.71 0.20 0.51 0.53 0.49]
[ 0.08 0.33 0.65 0.31 0.10 0.59 0.18 0.02 0.86 0.67]
[ 0.80 0.04 0.61 0.06 0.35 0.14 0.00 0.47 0.12 0.24]
]
uniform
static Matrix uniform({double lb = 0.0, double ub = 1.0, required int row, required int column, int? seed})
均匀分布
test
import 'package:flutter/material.dart';
import 'package:fl_chart/fl_chart.dart';
import 'flutter_matrix.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
useMaterial3: true,
),
home: const MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key});
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
// 生成1K个标准均匀分布的数据并且使用柱状图可视化
static Matrix datas = MatrixRandom.uniform(row: 1, column: 1000, seed: 42);
static Map<List<double>, int> maps = datas.toHist(start: 0.0, end: 1.0, counts: 10);
var ls = maps.keys.toList();
FlTitlesData get titlesData => FlTitlesData(
show: true,
bottomTitles: AxisTitles(
sideTitles: SideTitles(
showTitles: true,
reservedSize: 30,
getTitlesWidget: getTitles,
),
),
leftTitles: AxisTitles(
sideTitles: SideTitles(
showTitles: true, // 设置为 true 显示左侧 Y 轴刻度
reservedSize: 40, // 留出空间
interval: 3, // 设置刻度间隔
getTitlesWidget: getLeftTitles, // 自定义左侧刻度标签
),
),
topTitles: const AxisTitles(
sideTitles: SideTitles(showTitles: false),
),
rightTitles: const AxisTitles(
sideTitles: SideTitles(showTitles: false),
),
);
// 自定义 Y 轴刻度标签
Widget getLeftTitles(double value, TitleMeta meta) {
final style = TextStyle(
fontWeight: FontWeight.bold,
fontSize: 14,
);
String text;
if (value % 3 == 0) { // 仅在指定刻度显示标签
text = value.toInt().toString();
} else {
text = '';
}
return SideTitleWidget(
meta: meta,
space: 4,
child: Text(text, style: style),
);
}
Widget getTitles(double value, TitleMeta meta) {
final style = TextStyle(
fontWeight: FontWeight.bold,
fontSize: 14,
);
String text = ls[value.toInt()].toString();
return SideTitleWidget(
meta: meta,
space: 4,
child: Text(text, style: style),
);
}
List<BarChartGroupData> buildGroup(){
return List<BarChartGroupData>.generate(ls.length, (r){
return BarChartGroupData(
x: r,
barRods: [
BarChartRodData(toY: maps.values.elementAt(r).toDouble()),
]
);
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: BarChart(
BarChartData(
barGroups: buildGroup(),
titlesData: titlesData,
),
),
),
);
}
}
output
normal
static Matrix normal({double mu = 0.0, double sigma = 1.0, required int row, required int column, int? seed})
正态分布
test
static Matrix datas = MatrixRandom.normal(row: 1, column: 10000, seed: 42);
static Map<List<double>, int> maps = datas.toHist(start: -10.0, end: 10.0, counts: 100);
var ls = maps.keys.toList();
output
shake_total
void shake_total({double bias = 1.0, int? seed})
对整体数据随机上下限抖动最大abs(bias)值
test
import 'package:flutter_matrix/matrix_type.dart';
main() {
var mt = Matrix.fill(number: 2, row: 4, column: 6)..visible();
mt..shake_total(bias: 1, seed: 3)..visible();
}
output
[
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
]
[
[1.84526 1.93082 1.21542 1.07671 2.73399 1.04996]
[2.86985 1.04787 2.03070 2.86932 1.36468 2.91896]
[2.23152 2.47494 2.37738 2.75460 1.98057 2.90156]
[1.61362 1.21451 2.29266 1.64790 2.31230 1.48668]
]
shake_percent
void shake_percent({double bias = 1.0, double percent = 0.5, int? seed})
随机抖动percent占比的数据
test
import 'package:flutter_matrix/matrix_type.dart';
main() {
var mt = Matrix.fill(number: 2, row: 4, column: 6)..visible();
mt..shake_percent(bias: 1, seed: 3, percent: 0.5)..visible();
print(mt.count((x) => x == 2) == 4 * 6 ~/ 2);
}
output
[
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
]
[
[2.00000 2.00000 1.04996 1.04787 2.00000 1.21542]
[1.07671 2.00000 2.00000 2.86932 1.36468 2.03070]
[1.93082 2.86985 2.00000 2.91896 2.00000 2.00000]
[1.84526 2.00000 2.73399 2.00000 2.00000 2.00000]
]
true
shake_probably
void shake_probably({double bias = 1.0, double p = 0.5, int? seed})
按照概率对数据随机抖动
test
import 'package:flutter_matrix/matrix_type.dart';
main() {
var mt = Matrix.fill(number: 2, row: 4, column: 6)..visible();
mt..shake_probably(bias: 1, seed: 3, p: 0.25)..visible();
}
output
[
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
]
[
[2.00000 1.19765 2.00000 1.59960 2.00000 2.00000]
[2.00000 2.00000 2.00000 1.29358 2.16905 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
[2.00000 2.00000 2.00000 2.00000 2.00000 2.00000]
]
binomial
static Matrix binomial({required int n, required double p, required int row, required int column, int? seed})
二项式分布（伯努利分布），其中n是试验次数，p是成功的概率。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = '%2.0f';
var mt = MatrixRandom.binomial(n: 10, p: 0.6, row: 3, column: 6);
mt.visible();
}
output
[
[ 9 5 6 6 6 7]
[ 6 7 6 5 5 6]
[ 5 5 7 4 9 6]
]
chisquare
static Matrix chisquare({ required int df, required int row, required int column, int? seed })
卡方分布，其中正整数df是自由度。
test
import '../lib/flutter_matrix.dart';
main(){
var mt = MatrixRandom.chisquare(df: 3, row: 3, column: 6);
mt.visible();
}
output
[
[5.42309 5.67948 0.43278 9.90406 0.08491 0.75004]
[0.69392 1.83211 4.31445 3.21911 9.51412 7.66674]
[4.24697 0.43563 1.39504 4.06116 0.95671 3.23452]
]
exponential
static Matrix exponential({ required double lambda, required int row, required int column, int? seed })
指数分布，正实数λ是速率参数。
test
import '../lib/flutter_matrix.dart';
main(){
var mt = MatrixRandom.exponential(lambda: 3, row: 3, column: 7);
mt.visible();
}
output
[
[0.59205 0.30458 0.44661 0.37097 0.68382 0.37191 0.19418]
[0.87269 0.48058 0.11004 0.41595 0.09100 0.68939 0.04317]
[0.08204 0.16524 1.15535 0.70234 0.04674 0.30218 0.07011]
]
f
static Matrix f({ required int d1, required int d2, required int row, required int column, int? seed })
F 分布。其中 d1 和 d2 ] 是两个独立卡方分布的自由度。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.f(d1: 3, d2: 4, row: 4, column: 6);
mt.visible();
}
output
[
[ 0.92346 0.66244 3.03371 0.18384 0.63915 0.97611]
[ 0.91794 0.54395 0.33545 1.28692 0.01852 1.13263]
[ 2.17837 0.24876 3.40228 0.11621 0.76633 0.47811]
[ 1.02146 4.00121 0.25865 2.29399 2.07985 0.07998]
]
gamma
static Matrix gamma({ required double k, required double theta, required int row, required int column, int? seed })
伽马分布，其中k是形状参数，theta是尺度参数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.gamma(k: 2.3, theta: 1.2, row: 2, column: 9);
mt.visible();
}
output
[
[ 1.97898 2.11548 1.97235 2.01070 1.97023 2.15622 1.96931 1.96695 1.97193]
[ 1.99453 1.98793 1.98049 1.99853 2.01608 2.06490 1.96879 2.18777 2.01119]
]
beta
static Matrix beta({ required double a, required double b, required int row, required int column, int? seed })
贝塔分布，参数a和b分别是分子和分母的形状参数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.beta(a: 1.4, b: 1.5, row: 3, column: 6);
mt.visible();
}
output
[
[ 0.49674 0.47748 0.49000 0.51771 0.48358 0.53437]
[ 0.47219 0.48763 0.47852 0.48319 0.45656 0.46501]
[ 0.47745 0.47656 0.47766 0.48641 0.46924 0.47451]
]
dirichlet
static Matrix dirichlet({ required List
alpha, required int row, int? seed }) 狄利克雷分布，alpha参数是长度为列且不小于2的浮点序列，alpha中的每个数都必须大于0。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.dirichlet(alpha: [2, 3, 4, 5, 2, 1, 1, 9], row: 5);
mt.visible();
}
output
[
[ 0.06777 0.10927 0.14974 0.19033 0.06799 0.02707 0.03108 0.35675]
[ 0.06782 0.10716 0.15432 0.18717 0.07829 0.02750 0.02718 0.35056]
[ 0.07176 0.11077 0.14973 0.19066 0.06803 0.02759 0.02731 0.35416]
[ 0.06923 0.10830 0.15226 0.19454 0.06776 0.02710 0.02705 0.35375]
[ 0.06978 0.10861 0.14912 0.19070 0.06796 0.03449 0.02751 0.35182]
]
geometric
static Matrix geometric({ required double p, required int row, required int column, int? seed })
几何分布，其中p是成功的概率。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.0f";
var mt = MatrixRandom.geometric(p: 0.1, row: 4, column: 7);
mt.visible();
}
output
[
[ 1 3 1 1 33 2 15]
[ 4 3 2 6 1 12 18]
[ 24 2 6 9 33 7 2]
[ 6 7 11 5 16 4 10]
]
gumbel
static Matrix gumbel({ required double loc, required double scale, required int row, required int column, int? seed })
耿贝尔分布，其中loc是分布的众数的位置，scale是分布的尺度参数，并且必须为非负数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.gumbel(loc: 0, scale: 1, row: 2, column: 9);
mt.visible();
}
output
[
[-0.22699 -0.70834 2.46328 -0.27267 1.13736 -0.50648 0.10226 1.58143 3.05194]
[ 1.54331 -0.05892 0.14372 3.15481 0.44702 0.25944 -0.13567 0.74313 0.23801]
]
hypergeometric
static Matrix hypergeometric({ required int N, required int K, required int n, required int row, required int column, int? seed })
超几何分布，参数N、K、n分别表示元素总数、目标元素总数、抽取的样本数，最终得到样本中目标元素的数量。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.0f";
var mt = MatrixRandom.hypergeometric(N: 100, K: 10, n: 50, row: 6, column: 6);
mt.visible();
}
output
[
[ 2 8 6 6 5 3]
[ 4 4 2 7 3 5]
[ 6 2 2 7 6 3]
[ 3 5 5 7 6 7]
[ 7 8 6 7 5 5]
[ 5 4 7 8 4 3]
]
laplace
static Matrix laplace({ required double mu, required double b, required int row, required int column, int? seed })
拉普拉斯分布，又称双指数分布，mu是位置参数，非负数b是尺度参数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.laplace(mu: 1, b: 2, row: 2, column: 8);
mt.visible();
}
output
[
[ 5.15415 2.07610 -1.37176 -2.41060 -0.99129 3.98637 0.31916 0.24522]
[ 3.38619 4.86480 -1.78386 0.54009 -4.79726 4.24814 2.09560 2.00870]
]
logistic
static Matrix logistic({ required double mu, required double s, required int row, required int column, int? seed })
逻辑分布，其中mu和s分别是位置参数和尺度参数，s大于0。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.logistic(mu: 0, s: 1, row: 5, column: 6);
mt.visible();
}
output
[
[-2.34886 -0.62398 -0.72241 -0.47850 -3.57510 1.69050]
[-0.65039 2.70643 -3.55987 -0.00253 -1.33383 -1.94184]
[ 1.59177 2.44618 0.56556 -2.60605 -2.48145 0.41531]
[-0.63856 0.37617 0.94475 -2.98747 3.46455 0.92113]
[ 0.43686 -1.55776 1.55957 0.78217 -1.36549 -1.23248]
]
lognormal
static Matrix lognormal({ required double mu, required double sigma, required int row, required int column, int? seed })
对数正态分布，其中mu和sigma分别是位置参数和尺度参数，sigma大于0。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
var mt = MatrixRandom.lognormal(mu: 0, sigma: 1, row: 5, column: 6);
mt.visible();
}
output
[
[ 0.37147 0.43134 2.04398 0.59404 0.89507 0.46283]
[ 0.25305 3.53500 2.45734 0.25765 0.91990 1.25516]
[ 1.50877 2.68362 1.31308 2.22121 0.44431 1.59400]
[ 2.17962 4.71739 0.97841 0.41853 0.75954 1.39914]
[ 0.30549 1.09713 2.18105 0.99588 8.03950 1.81075]
]
multinomial
static Matrix multinomial({ required int n, required List
p, required int row, int? seed }) 多项式分布，其中n表示实验次数，p是概率列表且和为1。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.0f";
var mt = MatrixRandom.multinomial(n: 8, p: [0.15, 0.2, 0.1, 0.35, 0.05, 0.15], row: 5);
mt.visible();
}
output
[
[ 2 2 1 3 0 0]
[ 1 5 0 1 0 1]
[ 0 1 0 4 1 2]
[ 2 0 0 3 1 2]
[ 1 2 1 3 1 0]
]
poisson
static Matrix poisson({ required double lambda, required int row, required int column, int? seed })
泊松分布，参数lambda表示平均值。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.5f";
MatrixRandom.poisson(lambda: 3, row: 5, column: 9).visible();
}
output
[
[ 2.00000 7.00000 4.00000 3.00000 5.00000 5.00000 1.00000 3.00000 7.00000]
[ 1.00000 1.00000 2.00000 3.00000 5.00000 0.00000 2.00000 3.00000 5.00000]
[ 2.00000 4.00000 0.00000 0.00000 5.00000 1.00000 2.00000 2.00000 4.00000]
[ 1.00000 3.00000 5.00000 5.00000 4.00000 2.00000 4.00000 3.00000 5.00000]
[ 4.00000 3.00000 1.00000 2.00000 2.00000 3.00000 0.00000 2.00000 6.00000]
]
cauchy
static Matrix cauchy({ required double x0, required double gamma, required int row, required int column, int? seed })
柯西分布，参数x0是中心位置，正数gamma表示规模。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%3.5f";
MatrixRandom.cauchy(x0: 0, gamma: 1, row: 3, column: 7).visible(); // stand-cauchy-distribution.
}
output
[
[ -0.12131 9.06796 -3.06638 0.83097 1.10302 -0.78527 -1.10908]
[ 0.44494 5.59788 -5.16476 -3.09094 0.01960 2.58699 0.27861]
[ 0.01088 -0.87127 -2.68039 -0.02322 1.45664 -0.32921 0.25879]
]
pareto
static Matrix pareto({ required double xm, required double alpha, required int row, required int column, int? seed })
帕累托分布，xm是规模参数，正数alpha是形状参数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%3.5f";
MatrixRandom.pareto(xm: 0.5, alpha: 2, row: 3, column: 8).visible();
}
output
[
[ 1.63208 0.51504 0.51024 0.98437 0.52300 1.09564 1.39615 1.12143]
[ 0.66684 1.17252 0.50457 0.52373 0.61724 0.57446 0.66170 0.62191]
[ 0.51333 0.51563 0.66283 0.50024 0.52752 0.96687 0.63692 0.71290]
]
rayleigh
static Matrix rayleigh({ required double sigma, required int row, required int column, int? seed })
瑞利分布，正数sigma是规模参数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.2f";
MatrixRandom.rayleigh(sigma: 5, row: 2, column: 8).visible();
}
output
[
[ 4.14 4.63 11.24 13.64 10.93 2.56 7.49 3.43]
[ 3.73 1.64 8.93 3.25 9.83 5.23 4.97 11.78]
]
triangular
static Matrix triangular({ required double a, required double b, required double c, required int row, required int column, int? seed })
三角分布，下限为a，上限为b，众数为c。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.2f";
MatrixRandom.triangular(a: 1, b: 8, c: 5, row: 4, column: 8).visible();
}
output
[
[ 3.66 4.67 3.68 5.92 4.96 2.80 6.62 5.98]
[ 7.31 3.36 6.46 2.76 4.51 6.39 4.88 2.89]
[ 6.81 6.93 5.15 3.55 4.90 6.11 4.44 7.10]
[ 3.94 1.76 6.95 3.74 3.87 1.95 4.79 4.48]
]
wald
static Matrix wald({ required double mu, required double lambda, required int row, required int column, int? seed })
逆高斯分布（也称为Wald 分布），平均值mu和形状参数lambda均为正数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.2f";
MatrixRandom.wald(mu: 1, lambda: 2, row: 2, column: 6).visible();
}
output
[
[ 0.82 0.53 0.90 1.89 1.10 1.61]
[ 0.43 0.24 0.34 1.03 0.65 1.39]
]
weibull
static Matrix weibull({ required double k, required double lambda, required int row, required int column, int? seed })
韦伯分布，尺度参数lambda和形状参数k均为正数。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.2f";
MatrixRandom.weibull(k: 1, lambda: 2, row: 2, column: 6).visible();
}
output
[
[ 2.85 1.49 0.61 1.87 1.71 4.27]
[ 0.57 0.12 1.19 0.36 5.12 1.33]
]
vonmises
static Matrix vonmises({ required double k, required double mu, required int row, required int column, int? seed })
冯·米塞斯分布，参数mu和k分别表示位置和集中度，k>0。
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.2f";
MatrixRandom.vonmises(k: 1, mu: 0, row: 10, column: 10).visible();
}
output
[
[-0.09 -0.85 0.63 0.59 -1.30 0.48 1.02 0.81 -1.13 -0.08]
[ 0.51 -1.47 -0.11 0.69 -0.19 -0.04 0.49 0.96 0.20 0.82]
[-1.12 -0.84 -1.13 1.60 0.21 -0.55 -0.43 1.27 -1.41 1.64]
[-0.96 -1.76 -0.65 0.37 -0.57 0.09 0.30 -1.70 1.50 -0.22]
[-0.49 0.26 -0.54 -0.96 0.31 -0.89 -0.20 -1.15 0.23 0.55]
[ 1.09 -1.07 1.56 0.63 1.03 1.44 -1.46 0.61 -0.30 0.27]
[ 0.51 0.92 -1.11 -0.41 -1.37 -0.98 0.62 -0.66 -0.60 0.80]
[-0.55 -0.76 -0.45 0.42 0.01 0.13 -0.97 0.75 -0.94 -0.38]
[ 0.08 -0.89 -0.50 1.46 0.99 1.55 1.19 -1.71 -1.11 1.09]
[-1.14 -1.00 -1.91 -0.24 1.22 -0.36 -0.81 -0.55 -0.30 1.06]
]
t
static Matrix t({ required int v, required double mu, required int row, required int column, int? seed })
学生t分布，正整数v表示自由度，mu是非中心参数
test
import '../lib/flutter_matrix.dart';
main(){
data_format = "%2.2f";
var mt = MatrixRandom.t(v: 2, mu: 0, row: 5, column: 8);
mt.visible();
}
output
[
[-0.40 -0.42 -1.23 -2.11 -0.63 -0.29 -7.35 1.27]
[-0.62 0.82 0.98 1.41 -1.53 -4.18 -2.16 0.29]
[ 3.05 -1.58 -0.14 -1.29 -4.22 -4.17 -2.38 0.54]
[ 1.11 0.37 -0.79 2.72 -0.19 0.70 -0.38 -1.37]
[-0.36 -1.06 -1.33 1.33 -4.32 0.73 -1.34 0.06]
]